Transcatheter procedures have been a milestone advance in modern medicine. They have enabled minimally invasive procedures that reduce morbidity, improve recovery time, and permit interventions to be performed on subjects who are not otherwise candidates for surgery. Transcatheter procedures can be performed though rigid or flexible catheters. Advances in transcatheter procedures have been accompanied by challenges in developing technologies for remotely manipulating and modifying tissue and other objects within the body through the catheters. Transcatheter aortic and left heart procedures are generally performed through the femoral artery. However, femoral artery caliber or intravascular disease may preclude or complicate vascular access in a significant minority of candidates. For example, a common life-threatening risk of some transcatheter aortic heart valve procedures is vascular complications due to large introducer sheaths placed in the femoral artery.